In RS-485 to communicate, the long distance communication may produce high common voltage from ground resistance and current through the earth. This will cause the communication error.
For this solution, we usually use isolation way to eliminate the high common voltage. However, if there is a RS-485 transceiver can tolerate dozens of CMV, it may be another way to solve this kind of issue. MAX33072 is a right choice with up to +/-40V CMR.
After the customer's testing, we found that MAX33072 was able to solve this issue.